The antioxidant goodness of green tea is well documented. Scientists believe that the health benefits of reducing the risks of cancer, heart attack and stroke are due to the presence of antioxidants called catechins. The benefits, according to a study at Purdue University concluded that adding citrus juice (such as lemon or lime) to the tea will increase the absorbable catechin levels by more than five-fold. Additionally, the study suggested that taking vitamin C increases the absorbable levels of catechins up to thirteen times. According to Mario Ferruzzi, assistant professor of food science at Purdue, it may be that citrus juice and vitamin C act to preserve the catechins in the small intestines.
Ferruzzi was quoted as saying, "If you want more out of your green tea, add some citrus juices to your cup after brewing." His findings were published in Molecular Nutrition and Food Research.
Most tea growers take their task very seriously and put a lot of thought into the growing of green tea in order to maximize the presence of antioxidants. Based on the Purdue University study, it seems that with very little effort you can take a delicious and healthy product and multiply the benefits many-fold. If you want more information about green tea check out Wikipedia: Green Tea.